People purchase products from many different merchants using a variety of different payment options. The transactions for these purchases typically are confirmed by physical in-store receipts or by electronic confirmation messages that are addressed to the purchasers' messaging accounts (e.g., a purchaser's electronic mail account). The large number and diversity of confirmation messages makes it difficult for people to track their purchases and obtain a comprehensive understanding of their purchase histories. In addition, the large diversity of merchants from which people purchase products makes it difficult for merchants to obtain sufficient purchase history data to develop accurate customer profiles. Even assuming that a person uses a common identifier (e.g., a loyalty card or credit card) for all his or her purchases, these purchases typically are tracked only by the merchant that issued the identifier to the customer. This lack of customer information limits a merchant's ability to effectively target its promotions in ways that will encourage them to purchase the merchant's product offerings.
In an effort to ameliorate these problems, reporting systems have been developed to extract purchase related information from data sources that are published directly by merchants to consumers, such as purchase confirmation messages and shipping confirmation messages. However, these data extraction approaches breakdown if merchants fail to provide complete purchase transaction information to the consumers in one or more of such direct publishing channels. As a result, these systems are unable to provide complete cross-merchant purchase transaction information without requiring consumers to open membership accounts with all the merchants with which they shop and to further provide the reporting system with access to those accounts.